<?php
    /**
     * PHPExcel
     * Copyright (c) 2006 - 2015 PHPExcel
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     * This library is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category   PHPExcel
     * @package    PHPExcel_Shared
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version    ##VERSION##, ##DATE##
     */

    /**
     * PHPExcel_Shared_PasswordHasher
     * @category   PHPExcel
     * @package    PHPExcel_Shared
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     */
    class PHPExcel_Shared_PasswordHasher {
        /**
         * Create a password hash from a given string.
         * This method is based on the algorithm provided by
         * Daniel Rentz of OpenOffice and the PEAR package
         * Spreadsheet_Excel_Writer by Xavier Noguer <xnoguer@rezebra.com>.
         * @param     string $pPassword Password to hash
         * @return     string                Hashed password
         */
        public static function hashPassword($pPassword = '') {
            $password = 0x0000;
            $charPos  = 1;       // char position
            // split the plain text password in its component characters
            $chars = preg_split('//', $pPassword, -1, PREG_SPLIT_NO_EMPTY);
            foreach ($chars as $char) {
                $value        = ord($char) << $charPos++;    // shifted ASCII value
                $rotated_bits = $value >> 15;                // rotated bits beyond bit 15
                $value        &= 0x7fff;                    // first 15 bits
                $password     ^= ($value | $rotated_bits);
            }
            $password ^= strlen($pPassword);
            $password ^= 0xCE4B;
            return (strtoupper(dechex($password)));
        }
    }
